Excavator



April 27, 1937. c. E. STIEHL ET AL EXCAVATOR Filed NOV. 29, 1935 2 Sheets-Sheet 1 Patented Apr. 27, 1937 UNITED STATES PATENT OFFICE I EXOAVATOR I Delaware Application November 29, 1935, Serial No. 52,211

18 Claims.

to a point on the boom.known as the shipper shaft, the dipper being movable in a circle about this point as a center.

U. S. Patent No. 2,015,629, issued September 24, 1935, to Samuel Lippincott Griswold Knox, teaches the advantages of having the boom terminate at the shipper-shaft, and of having the hoist-line for the dipper pass over a sheave held out beyond the shipper-shaft by a light strut extending from the end of the boom, and of having the juncture of boom and strut supported from the main frame of the machine independently of the support of the outer end of the strut.

It is the principal object of the present invention to improve upon the.Knox front-end construction in various ways, including making provision for altering the distance of the sheave from the foot of the boom, either with or without 5 altering the inclination of the boom and/or the distance of the shipper-shaft from the foot of the boom; and also including an improved method of supporting the weight of the strut and boom, etc., from an elevated structure on the main 30 frame.

In addition to our principal objects, above for simplicity, is shown conventionalized.

Figure 2 is a side elevation of another embodiment of our invention, in which the suppc rting 50 frame, for simplicity, is shown conventionalized. Figure 3 is a side elevation of our supporting frame, unloaded.

Figure 4 is a side'elevation of our supporting frame, loaded.

55 Figure 5 is a plan view of the variant of either of our invention, in which the supporting frame,

Figure 1 or 2, omitting the adjustable feature, and also omitting the details of the supporting frame, the object of this figure being primarily to show the convergence of certain members, more particularly referred to in certain claims.

Figure 6 is a conventionalized elevation of the hydraulic apparatus associated with our telescoping boom foot.

Referring to the drawings, it will be seen that i i is the main base of an excavator, revolvable on a propelling base ill. I2 is a boom, pivoted at its foot to the base in any conventional manner, and inclined upwardly therefrom.

i3 is a hoist winch mounted on the base; but it is to be understood that direct mounting on the base is not essential, and that the winch may be mounted on any other part of the machine, which in turn is supported by the base.

it is a strut, secured to the outer end of the boom, for the purpose. of supporting the sheave l5. This strut may either be independent, or may constitute a part of the frame hereinafter described. I6 is a dipper handle, carrying at its outer end a dipper l1. I8 is a shipper-shaft, located adjacent the juncture of the strut I4 and the boom l2; 1. e., it may be carried byeither the strut or the boom, or both, or may be mounted in any other convenient manner in the immediate vicinity of the joint in question. "The method of drivingthis shipper-shaft is immaterial to the present invention. Thus it may be driven by a motor located adjacent to it, or (as shown in Figures 1 and 2) the reciprocation of the dipper handle maybe efiected by two ropes l9 and 20 passing around the sheaves 2| on the shipper-shaft, and anchored respectively to the front andrear'of the dipper handle, or thrusting can be effected by gravity and retraction by a single rope l9. Our claims are to be construed as including alternatively any method of reciprocating the dipper and handle.

A hoist-line 22 extends from the dipper and handle, over the sheave l5 to the winch iii.

The main frame II also carries an elevated structure 23, which may be, as shown, in the form of a conventional A-frame, or may take the form of a mast or any other conventional form.

Turning now to the first variant, namely that of Figure 1, and considering in this connection Figures 3 and 4. The shipper-shaft I8 in this case is carried by the boom l2 adjacent its outer end where it joins the-strut I4. The strut and the ,boom'are shown in Figure'l as apparently rigidly joined together, but it is to be understood that, in'view of the bending strains set up at this point by the operation of the machine, the boom and strut must be supported as though there were an actual free pivot at this point, and ac- 5 cordingly the term pivoted in our claims must be construed as including such a quasi-rigid joint as this.

A member 24 extends from the top of the A- frame 23 to this joint. A second member 25 exl0 tends from the top of the A-frame to substantially the outer end of the strut I4. Various crossmembers 26 are provided between members 24 and I4, and member 25.

Normally member I4, being supported at both ends and being-of considerable length and weight, will bow somewhat downward from the straight line 21, as shown in Figure 3.

Similarly member 24 (which is sometimes a tension member and sometimes a compression member, depending upon the outward or inward thrust of the dipper handle at the shipper shaft) will normally occupy a slightly bowed position, as shown in Figure 3; but this fact is relatively 25 immaterial to our present invention.

assume a bowed position from line 28, as shown in Figure 3, when under light tension. For the purposes of our invention, member 25 is preferably hinged in atleast one point, as at 29.

If the cross members 26 were omitted, the tremendous compressions imposed on strut I4,. when the dipper I1 is under load during digging, would tend to bend strut I4 even further than its normal position, and this bending tendency would require considerable strength to resist it. Ac-

cordingly the full advantage of the Knox patent already cited, in substituting this light strut for the outer half of the conventional boom, cannot be realized, without employing the features of our invention. 5

But, with the initially bowed position of memher 25, and the existence of cross-members 26,

Q then when member 25 straightens under the in- 45 creased tension of the added load, member I4 is compression now imposed on strut I4 by the added loadds imposed on a straight column, with no tendency to buckle. Accordingly this feature of our-invention enables us to build member I4 even more lightly than in the Knox patent referred to.

Every pound that can be taken-off the extreme front end of arevolving excavator, and especially an excavator of large size, is a vital'contribution to its emciency, by reducing its swinging moment.

There is a similar straightening effect on member 24, which similarly enables this member to be built more lightly, and yet still resist the digging thrusts which are imposed upon it; but this is relatively unimportant to the purposes of our invention.

In view of our employment of rigid members 24 and 25 in place of ropes, it is advisable to employ some other method of raising and lowering the boom, than the telescoping of these two members, although that would be a possible alternative. In this figure the lower apex of the triangular frame consisting of members I4, 24 and 25,'can-be se-- cured to the outer end of the boom at a number of alternative positions'indicated by 30 shifting to eitherof'the other two points 30 than the one where the attachment is shown in the picture as occurring, will, of course, throw the strut I4 I .of Figure 1. Member 25, which is a tension member, will also pulled straight by cross-members 26, so that the slightly out of alignment with the boom I2, but this is immaterial.

In Figure 2, on the other hand, this apexis fixed to the outer end of the boom at a single pivot point, and the boom itself is rendered telescoping in any convenient manner, as for example having the outer end of each leg of the boom constitute a piston 3I, and the lower end constitute a corresponding cylinder 32 of an hydraulic jack system. Turning now to Figure 6, we see that M is a' motor operating a hydraulic pump P which draws its liquid from a sump S through pipe 33. Pump P delivers, through pipe 34, to valve V, which can be selectively set to deliver through pipe 35 back to the sump S, at the same time closing pipe 36, or to deliver through pipe 36 to cylinders 32 to elongate the boom, or to drain the cylinders through pipes 36 and 35 into sump S to shorten the boom. The adjustment of the boom by means of these jacks, will cause the sheave I5 to occupy the alternative positions shown in dotted lines in Figure 2. A similar adjustment is possible by means of the alternative Turning now to Figure 5, which is a plan view of the variant of either Figure 1 or 2, omitting the adjustable feature, and also omitting the details of the supporting frame, we see that 23 is the A- frame. 25 are the tension members extending from the apex of the A-frame to adjacent the outer end of the strut I4. which extend from the apex of the A-frame to adjacent the juncture between the strut I4 and the boom I2.

It is to be noted that the strut I4 is relatively narrow throughout its entire length, and that the boom I2 converges from the widest possible bracing at its foot on the main frame II to the width of the strut I4 wherethese two members are pivoted together. It is also to be noted that the A-frame 23 is widely spaced, and that members 24 converge from its apex to their attachment to the boom and strut, and thatsirnilarly members 25 converge from the apex of the A- frame to their attachment to the strut I4.

Thus the boom I2 and members 24 together constitute a wedge-shaped support for the strut I4, the square base'of this wedge being widely braced on the main frame II and the A-frame 23.

This bracing, and the similar bracing of members 25, serve to resist the swinging moment of the extreme outer end of the excavating instrumentalities, while at the same time permitting a narrow and light construction to the strut I4.

Having now described and illustrated two forms of our invention, we wish it to be understood that our invention is not to be limited to the specific forms or arrangements of parts hereinbefore described, except in so far assuch limitations are specified in the appended claims.

We claim:

1. In a power shovel, the combination of: .a base; an .elevated structure thereon; a boom, pivoted at its foot to the base, and inclined upwardly therefrom; a hoist-winch; a strut, pivoted to the boom, selectively at any one of a plurality of distances from the boom foot; fixed length support means for the boom and the strut,-

extending from the elevated structure to substantially the juncture of the strut and the boom;

fixed length support means for'the strut, extendoi' the strut; a sheave, carried by the strut substantially at its upper end; a dipper-handle; I

24 are the members ing from the elevated structure to the upper end shaft, located substantially at the juncture of the strut and the boom; means for reciprocating the dipper handle; and a hoist-line, extending from the dipper and handle, over the sheave, to the winch.

i '2. In a power shovel, the combination of a base; an elevated structure thereon; a boom, piv"- oted at its foot to the base, and inclined upwardly therefrom; a hoist-winch; a strut, pivoted to the -boom, selectively at any one of a plurality of points substantially at the upper end of the boom; fixed length support means for the boom and the strut, extending from the elevated structure to substantially the juncture of the strut and the boom; fixed length support means for the strut, extending from the elevated structure to the upper end of the strut; a sheave, carried by the strut substantially at its upper end; a dipper-handle; a digging dipper, carried by the handle; a shipper-shaft, located substantially at the juncture of the strut and the boom; means for reciprocating the dipper handle; and a hoistline, extending from the dipper and handle, over the sheave, to the winch.

3. In a power shove], the combination of a base; an elevated structuretthereon; a telescoping boom, pivoted at its foot to the base, and in-. clined upwardly therefrom; a hoist-winch; a strut, pivoted to the boom, substantially at the upper .end thereof; support means for the boom and the strut, extending from the elevated structure to substantially the juncture of the strut and the boom; support means for the strut, extending from the elevated structure to the upper end of the strut; a sheave, carried by the strut substantially at its upper end; a dipper-handle; a digging dipper, carried by the handle; a shippershaft, located substantially at the juncture of the strut and the boom; means for reciprocating the dipper handle; and a hoist-line, extending from the dipper and handle, over the sheave, to the winch.

4:. In a power shovel, the combination of: a base; an elevated structure thereon; a boom, pivoted at its foot to the base, and inclined upwardly therefrom; ahoist-winch; a sheave; a triangular truss structure; one apex of which carrice the sheave, one apex of which is pivotally supported by the elevated structure, and the remaining apex oi which is pivoted to the boom selectively at any one of a plurality of distances from the boom foot; a dipper handle, a digging dipper, carried by the handle; a shipper-shaft, located substantially at the juncture of the truss apex and the boom; means for reciprocating the dipper handle; and a hoist-line, extending from the dipper and handle, over the sheave, to the winch.

5. In a power shovel, the combination of: a base; an elevated structure thereon; a boom, pivoted at its foot to the base, and inclined upwardly therefrom; a hoist-winch; a sheave; a triangular truss structure, one apex-of which carries the sheave, one apex of which lspivotally supported by the elevated structure, and the remaining'apex of which is pivoted to the boom selectively at any one of a plurality of points adjacent the upper end of the boom; a dipper-handle; a digging dipper, carried by the handle; a shippershaft, located substantially at the juncture of the truss apex and the boom; means for reciprocating the dipper handle; and a hoist-line, extending from the dipper and handle, over the sheave, to the winch.

6. In a power shovel, the combination of: a base; an elevated structure thereon; a telescoping boom, pivoted at itslfoot to the base, and inclined upwardly therefrom; a hoist-winch; a sheave; a triangular truss structure, one apex of which carries the sheave, one apex of which is pivoted to the elevated structure, and the remaining apex of which is pivoted to the boom adjacent the upper end thereof; a dipper-handle;

a digging dipper, carried by the handle; a shlp-- per-shaft, located substantially at the juncture of the truss apex and the boom; means for recipro- I sheave, to the winch.

7. In a power shovel, the combination of: a base; an elevated structure thereon; a boom, pivoted at its foot to the base, and inclined upwardly therefrom; a hoist-winch; a sheave; a triangular truss structure, one apex of which carries the sheave, one apex of which is pivotally supported by the elevated structure, and the remaining apex of which is pivoted to the boom selectively at any one of a plurality of distances from the boom foot; a dipper handle; a digging dipper, carried by the handlepa shipper-shaft, located substantially at the juncture of the truss apex and the boom; means for reciprocating the dipper handle; and a hoist-line, extending from the dipper and handle, over the sheave, to the winch; the triangular structure being characterized by the fact that the side thereof which extends from the elevated structure to the sheave is bowed downwardly when the hoist-line is not under digging tension, and straightens out when the hoist-line is under digging tension, thereby straightening out the side which extends from the boom to the sheave.

8. In a power shovel, the combination of: a base; an elevated structure thereon; a boom, pivoted at its foot to the base, and inclined upwardly therefrom; a hoist-winch; .a sheave; a triangular truss structure, one apex of which carries the sheave, one apex of which is pivotally supported by the elevated structure, and the remaining apex of which is pivoted to the boom; a dipper-handle; a digging clipper, carried by the handle; a. shipper-shaft, located substantially at the juncture of the truss apex and the boom;

means for reciprocating the dipper handle; and a hoist-line, extending from the dipper and handle, over the sheave, to the winch; the triangular structure being characterized by the fact that the side thereof which extends from the elevated structure to the sheave is bowed downwardly when the hoist-line is not under digging tension, and is cross-connected to the side which extends from the boom to the sheave, and straightens out when the hoist-line is under digging tension, thereby straightening out the side which extends from the boom to the sheave.

9. In a power shovel. the combination oi: a base; an elevated structure thereon; a boom, pivoted at its foot to the base, and inclined upwardly therefrom; a hoists-winch; a sheave; a triangular truss structure, one apex of which carries the sheave, one apex of which is pivotally sheave, to the winch; the triangular structure being characterized by the fact that the side thereof which extends from the elevated structure to the sheave is bowed downwardly when 5 the hoist-line is not under digging tension, and is cross-connected to the other two sides, and straightens out when the hoist-line is under digging tension, thereby straightening out the other two sides. I 10. A support for the shipper-shaft and hoistsheave of a power-shovel, comprising: a boom; a strut, pivoted to the boom, selectively at any one of a plurality of distances from the boom foot; fixed length support means for the boom and the strut, connected to one of them at substantially their juncture; fixed length support means for the strut, connected to it at substantially its outer end; sheave support means, carried by the strut substantially at its outer end; and shipper-shaft support ,means, substantially at the juncture of boom and strut.

11. A support for the shipper-shaft and hoistsheave of a power-shovel, comprising: a boom;

a strut, pivoted to the boom; selectively at any one of a plurality of points adjacent the upper end of the boom; fixed length support means for the boom and the strut, connected to one of them at substantially their juncture; fixed length support means for the strut, connected to it at substantially its outer end; sheave support means, carried by the strut substantially at its outer end; and shipper-shaft support means, substantially at the juncture of boom and strut.

12. A support for the shipper-shaft and hoistsheave of a power-shovel, comprising:' a telescoping boom; a strut, pivotable to the boom, adjacent the upper end thereof; support means for the boom and the strut, connected to them at substantially their juncture; support means for 40 the strut, connected to it at substantially its outer end; sheave support means, carried by the strut substantially at its outer end; and shipper-shaft support means, substantially at the juncture of boom and strut.

13. A support. for the shipper-shaft and hoistsheave of a power-shovel, comprising: a boom; and a triangular truss structure, one apex of which carries the sheave, one apex of which is pivotally supported by the elevated structure,- v 50 and the remaining apex of which is pivoted to the boom selectively at any one of a plurality of distances from the boom foot; the shipper-shaft being supportable substantially at the juncture of boom and truss apex. 1 5 14. A support for the shipper-shaft and hoist-sheave of a power-shovel, comprising: a boom; and a triangular truss structure, one apex of which carries the sheave, one apex of which is pivotally supported bythe elevated structure, 0 and the remaining apex of which is pivoted to the boom selectively at any one of a. plurality of points substantially at the upper end of the boom; the shipper-shaft being supportable substantially at the juncture of boom and truss apex. I 15. A support for the shipper-shaft and hoistsheave of a power-shovel, comprising; a telescoping boom; and a triangular truss structure. one apex of which carries the sheave, one apex of which is pivotally supported by the elevated structure, and theremaining apex of which is pivoted to the boom substantially at the outer end thereof; the shipper-shaft being supportable substantially at the'juncture of boom and truss apex.

16. A support for the shipper-shaft and hoistsheave of a power-shovel, comprising: a boom; and a triangular truss structure, one apex of which carries the sheave, one apex of which is pivotally supported by the elevated structure, and

the remaining apex of which is pivoted to the boom; the triangular structure being characterized by the fact that the side thereof which extends'from the elevated structure to the sheave is bowed downwardly when the hoist-line is not under digging tension, and is cross-connected to the side which extends from the boom to the sheave, and straightens out when the hoist-line is under digging tension, thereby straightening out the side which extends from the boom to the sheave.

17. In a power shove], the combination of a base; an elevated structure thereon; a boom, having a relatively wide foot and converging upwardly therefrom, said relatively wide foot being pivoted to the base; a hoist-winch; a strut,

combination with the boom, together constitut- 5 ing a wedge, supported at its quadrilateral base, and supporting at its apex edge the strut; outwardly converging support means for the strut,

extending fromthe elevated structure to the upper end of the strut; asheave, carried by the strut substantially at its upper end; a dipper-ham die; a digging dipper, carried by the handle; a shipper-shaft, located adjacent the juncture of the strut and the boom; means for reciprocating the dipper-handle; and a hoist line, extending from the dipper and handle, over the sheave, to the winch.

18. In a power shovel, the combination of: a base; an elevated structure thereon; a hoistwinch on the base; a strut; a wedge-shaped supporting structure for the lower end of the strut, having its wedge edge secured to the strut, two corners of its rear end secured to the base, and two corners of its rear end secured to the elevated structure; support means for the upper end of vthe strut, extending from the elevated structure to substantially the upper end of the strut; a sheave, carried by the strut substantially at its upper end; a dipper-handle; a digging dipper, carried by the handle; a shipper-shaft, located substantially at the lower end of the strut; means for reciprocating the dipper handle; and a hoistline, extending from the dipper and handle, over the sheave, to the winch.

CARL E. STIEHL. WERNER LEHMAN. 

